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Re: Server-Sent Events contradiction

From: Ian Hickson <ian@hixie.ch>
Date: Wed, 2 Jan 2013 22:23:21 +0000 (UTC)
To: Bill Thiede <w3@xinu.tv>
cc: public-webapps@w3.org
Message-ID: <Pine.LNX.4.64.1301022213050.12992@ps20323.dreamhostps.com>
On Sun, 30 Dec 2012, Bill Thiede wrote:
>
> The Server-Sent Events at 
> http://www.w3.org/TR/2012/CR-eventsource-20121211/ states under the IANA 
> considerations / Security considerations section:
> 
> "Servers can be overwhelmed if a situation develops in which the server 
> is causing clients to reconnect rapidly. Servers should use a 5xx status 
> code to indicate capacity problems, as this will prevent conforming 
> clients from reconnecting automatically."
> 
> However, under section "5 Processing model" it is stated:
> 
> "HTTP 500 Internal Server Error, 502 Bad Gateway, 503 Service 
> Unavailable, and 504 Gateway Timeout responses, and any network error 
> that prevents the connection from being established in the first place 
> (e.g. DNS errors), must cause the user agent to asynchronously 
> reestablish the connection."
> 
> My guess is section 5 was updated more recently and the IANA section was 
> overlooked.  I know there are 5xx errors not listed explicitly, which 
> would then trigger the "Any other HTTP response code not listed here 
> must cause the user agent to fail the connection," but I doubt that a 
> 501 or 505 are the suggested solution here.

Good catch.

Since none of the browsers I could test reconnect for 500s currently as 
far as I can tell, I've changed the spec to not make 5xxs reconnect. The 
server load issue seems like a pretty big deal. It still says to reconnect 
in the case of an interrupted connection though, or if the connection 
couldn't be established in the first place, so going through a tunnel 
should still work fine.

Updated text is at:

   http://whatwg.org/html#event-source-network-errors-reconnect


> PS I'm emailing, because the 'Feedback Comments' form on the web page 
> returned 'ERROR' on my attempt to submit.  Not sure who to notify of 
> that problem.

The error reporting widget on the WHATWG spec above should work, FWIW. 
E-mail is fine too though.

-- 
Ian Hickson               U+1047E                )\._.,--....,'``.    fL
http://ln.hixie.ch/       U+263A                /,   _.. \   _\  ;`._ ,.
Things that are impossible just take longer.   `._.-(,_..'--(,_..'`-.;.'
Received on Wednesday, 2 January 2013 22:23:43 GMT

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